Pension and Other Postretirement Benefits (Summary of Weighted-Average Assumptions to Determine Benefit Obligations) (Details)	Dec. 31, 2012	Dec. 31, 2011
Webster Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	4.35%
Webster State Earnings Related Pension Scheme [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.40%	4.00%
Other Pension Plans, Postretirement or Supplemental Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.85%	3.60%